Hey John.  I got a brilliant idea from Dan Fleming.
Purchase a length (25') of outdoor extension cord from your friendly
local hardware store.  Cut the ends off, cut it in half, and you
should have 2 pieces of shielded cable with 3 wires in each.  These
work great for running under the van and up to the dash.  I do this as
part of subaruvanagon conversions to provide wiring for aftermarket
gauges.  Typically run from the black plastic junction box in the
engine bay to the dashboard through a grommet which exists just behind
the drivers side headlight.

Works great and much less expensive than buying wiring on the spool.

pictures here....
http://www.weidefamily.net/vanagon/Pending_Content/Engine_Conversion/06RunWiresToDashAftermarketGauges

all the best,
brent
--
Brent Weide
Portland, Oregon
www.weidefamily.net/vanagon/